A single-input multiple-output (SIMO) system is a wireless communication technology in which a transmitting side uses one antenna and a receiving side uses several antennas. In this technology, a method in which a receiving side uses a signal having the best characteristic among several signals that are transmitted in the SIMO system is called a diversity system. In the diversity system, as a representative, a maximum ratio combining (MRC) method, which combines respective received signals with proper weight values given thereto, has been used.
However, in the case of using the MRC method, the received signals are combined under the assumption that noise or interference that is estimated on the receiving side is accurate. However, in an actual mobile communication system, there has been a need for a technology that considers the noise, interference, and delay offset between the signals received from the several antennas.